Bi4Ti3O12 (BIT) coprecipitated powders sinter in the presence of a transitory liquid phase, which strongly enhances the diffusion of matter and also the anisotropic growth of BIT grains. However, by coating the surface of BIT particles with WO3 the aspect ratio of the platelets can be controlled. This, in addition to the donor effect of tungsten, finally leads to a decrease of the electrical conductivity of these ferroelectric ceramics.